1. Field of the Invention
The present invention is directed to a centrifugal clutch comprising a housing arrangement, a pressing plate which is coupled with the housing arrangement so as to rotate together with the housing arrangement around an axis of rotation and is movable in the direction of the axis of rotation, a supporting member which is movable axially with respect to the housing arrangement, and a plurality of centrifugal members, each of which is supported with respect to the housing arrangement in a first supporting area extending radially from inside to outside and is supported with respect to the supporting member in a second supporting area extending radially from inside to outside. An axial distance between the first supporting area and the second supporting area of a pair of supporting areas associated with each centrifugal member decreases radially from inside to outside, and every centrifugal member is radially displaceable by centrifugal force along the pair of supporting areas associated with it.
2. Description of the Related Art
A friction clutch which can be activated by centrifugal force is known from DE 30 19 377 A1. By means of this known centrifugal clutch, a flywheel which is otherwise freely rotatable is suddenly coupled to a crankshaft of an internal combustion engine when a determined limiting speed of the flywheel is reached in order to generate a drive torque which cranks this crankshaft and accordingly starts the internal combustion engine. The roller elements acting as centrifugal members are supported with respect to a housing associated with the flywheel on the one hand and with respect to a plate-like supporting element on the other hand, these two structural component parts or structural component groups having supporting areas which approach one another in radial direction toward the outside. The plate-like supporting element which is not otherwise supported in the entire arrangement is supported in axial direction at a plate spring that is secured axially in its radial outer area with respect to the flywheel and, therefore, also with respect to the housing. This plate spring in turn acts upon the pressing plate in axial direction, namely, in the present case, by means of another plate spring. Accordingly, these two plate springs permanently generate a force which pretensions the supporting element in the releasing direction so that it is also ensured that the centrifugal members are positively pretensioned toward the radial inside and held in their radial innermost position when there is no centrifugal force applied.
Due to this substantially loose arrangement of the plate-like supporting element, slight manufacturing inaccuracies or inaccurate positioning can have the result that the different centrifugal members do not move radially outward in a uniform manner when a slight tilting movement occurs. The centrifugal members are pressed radially outward to a greater extent in those places where the supporting element is at a greater distance from the housing than in other areas due to slight tilting and the centrifugal members are therefore also exposed to greater centrifugal force. This leads to a more sharply inclined position and to a correspondingly asymmetric action upon the pressing plate. Consequently, on the one hand, an uneven loading of the pressing plate may possibly occur and, on the other hand, variations may be generated in the transmission of torque which could result in a grabbing of the clutch.